Yandex.Tank is an extendable open source load testing instrument for advanced linux users which is especially good as a part of automated load testing suit.
[Jenkins](http://jenkins-ci.org/) An extendable open source continuous integration server that may be used to automate test execution.
[Graphite](http://graphite.readthedocs.org/en/latest/overview.html) is an enterprise-scale monitoring tool, use it to store your test results and render graphs.